<template>
    <el-container class="home-container">
        <!-- 头部区域 -->
        <el-header>
            <div>
                <img src="../assets/logo.png" alt="">
                <span>电商后台管理</span>
            </div>
            <el-button type="info" @click="layout">退出</el-button>
        </el-header>

        <el-container> 
            <!--侧边栏--> 
            <!-- <el-aside width="200px"> -->
            <el-aside :width="isCollapse ? '64px' : '200px'">
                <div class="toggle-button" @click="toggleCollapse">|||</div>
                <!--侧边栏菜单区域 -->
                <!--  default-active="1"  -->
                <el-menu 
                background-color="#333744" 
                text-color="#fff" 
                active-text-color="#409EFF"
                unique-opened
                :collapse="isCollapse"
                :collapse-transition="false"
                :router="true"
                :default-active="activePath"
                >
                <!--一级菜单-->
                <el-submenu :index="item.id+''" v-for="item in menuList" :key="item.id" >
                    <!--一级菜单模板区域-->
                    <template slot="title">
                        <!--图标-->
                        <i :class="iconsObj[item.id]"></i>
                        <!--文本-->
                        <span>{{item.authName}}</span>
                    </template>
                    <!--二级菜单-->
                    <el-menu-item :index="'/'+subItem.path" v-for="subItem in item.children" :key="subItem.id"
                    @click="saveNavState('/'+subItem.path)"
                    >
                        <!--二级菜单模板区域--> 
                        <template slot="title">
                            <!--图标-->
                            <i class="el-icon-menu"></i>
                            <!--文本-->
                            <span>{{subItem.authName}}</span>
                        </template>
                    </el-menu-item>
                    </el-submenu>
                </el-menu> 
            </el-aside>

            <!-- 右侧内容主体区域 -->
            <el-main>
                <!-- 路由占位符 -->
                <router-view></router-view>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
    export default {
        data(){
            return{
                // 左侧菜单数据 
                menuList:[],
                // 以对象的形式的数组iconsObj
                iconsObj:{
                    '125':'iconfont icon-user',
                    '103':'iconfont icon-tijikongjian',
                    '101':'iconfont icon-shangpin',
                    '102':'iconfont icon-danju',
                    '145':'iconfont icon-baobiao',
                },
                // 是否折叠
                isCollapse:false,
                // 被激活的链接地址
                activePath:''
            }
        },
        // 周期函数created,页面加载时自动调用
        created(){
            this.getMenuList();
            // this.activePath.push('/login')
            this.activePath=window.sessionStorage.getItem('activePath');

        },
        methods: {
            layout(){
                // 清除token
                window.sessionStorage.clear();
                //编程时导航回到登录页面
                // 这是路由接口路径与改变根路径无关
                this.$router.push('/login');
            },
            // 获取所有菜单数据
            //async await 使Promise对象简化
            async getMenuList(){ 
                // 发送请求获取左侧菜单数据  
                // {data}  (data+{}) 获取到后面对象的data属性 
                // {data:res} 等价于  res = {data}
                const {data:res}=await this.$http.get('/menus');
                // console.log(res);
                if(res.meta.status!==200)return this.$message.error(res.meta.$msg)
                this.menuList=res.data;
                // console.log(this.menuList);
            },
            // 点击按钮，切换菜单折叠与展开
            toggleCollapse(){
                this.isCollapse=!this.isCollapse
            },
            // 保存链接的激活状态
            saveNavState(activePath){
                window.sessionStorage.setItem('activePath',activePath)
                // 重新赋值
                this.activePath=activePath
            }

        },
    }
</script>

<style scoped>
.home-container{
    height: 100%;
}
.el-header{
    background-color: #373d41;
        /*弹性和模型布局*/
    display: flex;
    justify-content: space-between;
    color: #fff;
    align-items: center;
    padding-left: 0;
    font-size: 20px;
}
.el-header div {
    display: flex;
    align-items: center;
}
.el-header div span {
    margin-left: 20px;
}
.el-header img {
    width: 50px;
    height: 50px;
}
.el-aside{
    background-color: #333744;
}
.el-main{
    background-color: #eaedf1;
}
.toggle-button{
    background-color: #4a5064;
    font-size: 10px;
    line-height: 24px;
    color: #fff;
    text-align: center;
    letter-spacing: 0.2em;
    cursor: pointer;
}

</style>